Dewoitine D.520
Encyclopedia
The Dewoitine D.520 was a French
fighter aircraft
that entered service in early 1940, shortly after the opening of World War II
. Unlike the Morane-Saulnier M.S.406
, which was at that time the Armée de l'Airs most numerous fighter, the Dewoitine D.520 came close to being a match for the latest German
types, such as the Messerschmitt Bf 109
. It was slower than the Bf 109E but superior in manoeuvrability. Because of a delayed production cycle, only a small number were available for combat with the Luftwaffe
.
The D.520 was designed in response to a 1936 requirement from the Armée de l'Air for a fast, modern fighter with a good climbing speed and an armament centred around a 20 mm cannon. At the time the most powerful V 12
liquid cooled engine available in France was the Hispano-Suiza 12Y
, which was less powerful, but lighter, than contemporary engines such as the Rolls-Royce Merlin
and Daimler-Benz DB 601
. Other fighters were designed to meet the specifications but none of them entered service, or entered service in small numbers and too late to play a significant role during the Battle of France
.
. The specifications called for a maximum speed of 500 km/h (310.7 mph) at 4000 m (13,123.4 ft), the ability to climb to 8000 m (26,246.7 ft) in less than fifteen minutes, with take-off and landing runs not exceeding 400 m (1,312.3 ft). The armament was to be two 7.5 mm (.295 in) machine gun
s and one 20 mm Hispano-Suiza HS.9 cannon
, or two HS.9 cannon. Dewoitine had been disappointed with the performance of his last design, the Dewoitine D.513, which was rejected by the Armée de l'Air in favour of the Morane-Saulnier M.S.406
, and decided to respond to the specifications with a design using the latest construction techniques and the most powerful available engine, the new 660 kW (890 hp) Hispano-Suiza 12Y-21 liquid-cooled engine. The first design was rejected by the l'Air Ministry, which, after being impressed by the British Hawker Hurricane
and Supermarine Spitfire
, then uprated the specifications to include a maximum speed requirement of 500 km/h (310.7 mph). In response, Dewoitine renamed the further development, the "D.520".
Other aircraft designed to the same specification included the Morane-Saulnier M.S.450, the Loire-Nieuport 60 (later C.A.O 200, and the Caudron-Renault C.770
, none of which either left the drawing board or entered service. Two other concurrent French designs, the Bloch MB.152.01 and Bloch MB.155.C1 series and the Arsenal VG.33 entered service in small numbers with the Armée de l'Air during the Battle of France
, but too late to play a significant role.
In March 1937 the firm was conglomerated into one of a number of design-and-manufacturing pools, in this case SNCAM
. Because of this and continued changes in the Armée de l'Air's manufacturing programmes, work on the design of the D.520 was suspended throughout much of 1937, and it was not until January 1938 that a small number of draughtsmen started work on the first detail drawings for the prototype
. This prototype, D.520-01, powered by a Hispano-Suiza 12Y-21 temporarily driving a fixed-pitch, two bladed wooden propeller, first flew on 2 October 1938, but only managed to reach 480 km/h (298.3 mph) in flight tests, and suffered from dangerously high engine temperatures. Most of the problem was judged to come from greater than expected drag
from the underwing radiator
s, which exhausted across the upper wing surface, and these were replaced with a single radiator unit housed under the fuselage
in a streamlined fairing. After minor damage in a landing accident, further modifications included changing the engine to a newer -29 model and incorporating exhaust ejectors for added thrust, along with a three-blade variable pitch propeller. These changes were enough to allow the aircraft to reach its design speed, achieving 530 km/h (329.3 mph). The maximum diving speed was 825 km/h (512.6 mph).
The prototype was followed in 1939 by two examples: D.520-02 and 03, first flown on 9 January and 5 May 1939 respectively, featuring new sliding canopies, a larger tail unit, and longer Olaer manufactured undercarriage legs; they also omitted the Handley-Page slats
fitted to the outer wings on 01. These prototypes were armed with the 20 mm Hispano-Suiza HS.9 cannon in a moteur-canon mount in which the barrel was mounted in a sleeve between the cylinder banks and fired through the propeller spinner. and two MAC 1934
7.5 mm (.295 in) machine gun
s, each initially with 300 rounds per gun, housed in small pods under the wing. The third prototype also introduced a small tailwheel instead of the original skid. The second prototype was later fitted with a Hispano-Suiza 12Y-31 engine and achieved a maximum speed of 550 km/h (341.8 mph) and reached 8000 m (26,246.7 ft) in 12 minutes 53 seconds. Flight tests proceeded successfully, resulting in a contract issued in March 1939 for 200 production machines to be powered by the newer -31 engine (later replaced by the -45). A contract for an additional 600 aircraft was issued in June, albeit reduced to 510 in July 1939.
With the outbreak of war, a new contract brought the total of D.520s on order to 1,280, with the production rate to be 200 aircraft per month from May 1940. The Aéronautique Navale
then ordered 120. Another Armée de l'air order in April 1940 brought the total to 2,250 and increased production quotas to 350 a month.
The first production D.520 flew in October 1939. On production aircraft, the rear fuselage was extended by 51 cm (20.1 in), the engine cowling panels were redesigned, the curved, one-piece windshield was replaced by one containing an optically flat panel and armour plate was fitted behind the pilot's seat. Most production examples were powered by the 935 CV Hispano-Suiza 12Y-45 with the new Szydlowski
-Planiol supercharger
, although later production versions used the 960 CV Hispano-Suiza 12Y-49. The production standard armament was a 20 mm HS.404 cannon firing through the propeller hub and four belt-fed MAC 1934 M39 7.5 mm (.295 in) machine guns in the wings.
As the first batch of D.520s rolled off the production lines, they failed acceptance tests due to insufficient top speed and troublesome cooling. Redesigned compressor intakes, a modified cooling circuit and propulsive exhaust pipes proved to be effective remedies for these shortcomings, but as early examples had to be retrofitted with these improvements, the type was not declared combat ready until April 1940.
The Hispano-Suiza 12Y-45 engine was an underpowered, older design, with 850 CV at takeoff at 2,400 rpm, or 935 CV emergency power at 2,520 rpm and at a height of 1900 m (6,233.6 ft). The Hispano engine had some advantages over some later engines; for example, the weight was only 515 kg (1,135.4 lb), compared to the 620 kg (1,366.9 lb) of the Rolls-Royce Merlin III. Fuel was fed via six Solex
S.V. 56 carbureteurs mounted on an inlet manifold which directed compressed air from the supercharger to the engine cylinders; the 12Y-45 and -49s fitted to production D.520s used either 92 or 100 octane
fuel. The -45 drove an electrically operated Ratier Type 1606M three-bladed, 3 m (9.8 ft) diameter, variable pitch propeller, while D.520s from № 351 were fitted with the 12Y-49 960 CV engine driving a Chauvière type 3918 pneumatically operated propeller, also 3 m (9.8 ft) in diameter.
The D.520 had a fire suppression system with a fire extinguisher activated from the cockpit. The engine was started by a simple but effective system, operating with compressed air. A Viet 250 air compressor charged several air bottles (one with 12 l capacity, as well as another 8 l tank, three smaller 1 l units matched to the weapons). The 12 l air bottle was used for the brakes and later, for the Chauvière propeller's constant speed adjustment. The small air bottles provided up to 12 seconds at 9000 m (29,527.6 ft) or 20 seconds pressure at low level, before the Viet air compressor re-charged them. The pilot had a complete set of cockpit instruments, and a 10 l oxygen bottle located in the fuselage just behind his seat, with either Munerelle or Gourdou oxygen regulator systems mounted on the right instrument panel. Equipment included a Radio Industrie Type Rl 537 radio-receiver set, an OPL RX 39 reflector sight
(less effective than the Revi system), a height adjustable seat, and a sliding canopy with large, clear panels. Except over the long nose, the pilot's view was good, since the pilot was seated quite high over the forward fuselage, however, no rear-facing mirrors were fitted.
Production-standard armament consisted of a 20 mm HS.404 moteur-canon, with an ammunition capacity of 60 rounds, firing through the propeller hub, and four belt-fed MAC 1934 M39 7.5 mm (.295 in) machine guns in the wings, each with 675 rounds per gun. The MAC 1934 machine guns had a high rate of fire
of 1,200 rounds per minute (rpm), while the effective HS.404 fired at 600 rpm and was accurate up to 500 m (1,640.4 ft); the ammunition capacity meant that the MAC 1934s could be fired for a total of 30 seconds, while the HS. 404 had 10 seconds worth of ammunition. In combat the MS.406 had only two 7.5 mm and was, therefore, at a disadvantage when the HS.404 had used up its ammunition, while a D.520 could continue to fight effectively because it had four fast-firing machine guns (over 80 rounds/sec), with 20+ seconds of ammunition still available. The D.520 had provisions for two BE33 "illuminating bombs", useful for nocturnal interception missions, but these were rarely used because French fighters rarely flew night-time missions.
The D.520 was designed to be maintained easily with many inspection panels, a rare feature for its time. Re-charging the D.520 ammunition was swift and easy; the machine gun magazines required five minutes each and three minutes for the 20 mm cannon. To fill the machine gun ammunition boxes took 15 minutes, while five minutes were needed to empty the 20 mm box (the cartridges were not expelled). The D.520's cockpit was set well back in the fuselage, aft of the trailing edge. That gave the pilot good downward visibility, but the long nose in front of him was a drawback when taxiing on the ground.
Production was optimized with a reduced 7,000 man/hour each, roughly half the time compared to the previous D.510 and MS.406, and far less many other fighters of the time, such as the MC.200/202 (21,000 hours), but around 50% more than a Bf 109E (4,500 hours). The French Air Ministry planned for over 300 aircraft/month and managed to reach this goal, especially in June 1940, but it was too late to affect the tide of battle.
After the armistice with Germany, a further 180 machines were built, bringing the production total to 905.
Although employing a modern design philosophy for its time, the D.520 was considered more difficult to fly than the older MS.406. Capt. Eric Brown, commanding officer of the RAF's Captured Enemy Aircraft Flight, tested the D.520 at RAE Farnborough, saying that “It was a nasty little brute. Looked beautiful but didn’t fly beautifully. Once you get it on the ground, I was told not to leave the controls until it was in the hangar and the engine stopped. You could be taxiing toward the hangar and sit back when suddenly it would go in a right angle.”
was the first unit to get the D.520, receiving its first aircraft in January 1940. These were unarmed and used for pilot training. In April and May 1940, operational units received 34 production D.520s; the type proving to be very popular with the pilots. In comparative trials on 21 April 1940 at CEMA at Orleans-Bricy against a captured Bf 109E-3, the German aircraft had a 32 km/h (20 mph) speed advantage owing to its more powerful engine. However, the D.520 had superior maneuverability, matching its turning circle, although displaying nasty characteristics when departing and spinning out of the turn repeatedly during the tests. The Bf 109, owing to its slats
, could easily sustain the turn on the edge of a stall.
By 10 May 1940, when Germany invaded France and the Low Countries, 228 D.520s had been manufactured, but the Armée de l'Air had only accepted 75, as most others had been sent back to the factory to be retrofitted to the new standard. As a result, only GC I/3 was fully equipped, having 36 aircraft. They met the Luftwaffe on 13 May, shooting down three Henschel Hs 126
s and one Heinkel He 111
without loss. Four more Groupes de Chasse and three naval Escadrilles rearmed with the type before France's surrender. GC II/3, GC III/3, GC III/6 and GC II/7 later completed conversion on the D.520. A naval unit, the 1er Flotille de Chasse, was also equipped with the Dewoitine. But only GC I/3, II/7, II/6 and the naval AC 1 saw any action in the Battle of France
. GC III/7 converted to the D.520 too late to be involved in combat.
In air combat, mostly against Italians, the Dewoitine 520s claimed 114 air victories, plus 39 probables. Eighty five D.520s were lost. By the armistice at the end of June 1940, 437 D.520s had been built with 351 delivered.
After the armistice, 165 D.520s were evacuated to North Africa. GC I/3, II/3, III/3, III/6 and II/7 flew their aircraft to Algeria to avoid capture. Three more, from GC III/7, escaped to Britain and were delivered to the Free French. A total of 153 D.520s remained in mainland France.
One of the most successful D.520 pilots was Pierre Le Gloan
, who shot down 18 aircraft (four Germans, seven Italian and seven British), scoring all of his kills with the D.520, and ranked as the fourth-highest French ace of the war.
authorities to resume production of a batch of 1,000 military aircraft for their own use, under the condition that 2,000 German-designed aircraft would later be manufactured in France and delivered to Germany. As part of this agreement, 550 examples of the D.520 were ordered to replace all other single-seat fighters in service. The plan was to have the Dewoitine eventually equip a total of 17 Groupes with 442 aircraft, three escadrilles of the Aéronautique navale with 37 aircraft each, plus three training units with 13 aircraft. The agreement stated that aircraft of this new batch were to be similar to the ones already in service. . From serial number 543 on, however, D.520s used the 12Y-49 engine that had a slightly higher rated performance than the 12Y-45, although the German Armistice Commission
explicitly prohibited replacing the original engines with the more powerful 12Y51 or 12Z engines.
In 1941, D.520s of GC III/6, II/3 and naval escadrille 1AC fought the Allies during the Syria-Lebanon campaign
. The Vichy French Air Force
(Armée de l'Air de Vichy) was already relatively strong, but several units were sent to reinforce it. D.520s were the only French single-seat fighters capable of making the trip to Syria. The GC III/6 was sent first. The ferry trip was very difficult for a 1940 interceptor and the pilots pushed their planes as far as their fuel tanks would allow them to. They flew from France to Syria with intermediate stops at Rome, Brindisi or Catania. Another route was available through Germany and Greece (Athens), but it was seldom used. The trip always included a stopover in Rhodes (once an Italian base), before the final flight to Syria. This meant several thousands of kilometers were flown over mountains and sea. The most demanding part was Catania-Rhodes, which entailed no less than 1,200 km flown over the sea. Even the trip from Rhodes to Syria was 800 km. LeO 451s and Martin 167F bombers had few problems, but D.520s were forced to fly a strenuous and dangerous mission, without any help or external assistance. Of the 168 French aircraft (of all types) sent to Syria, 155 accomplished their mission and successfully arrived. The Vichy Air force was numerically strong, but with very few ground crew and spare parts, so the operational flying time for the D.520s was very limited. D.520s of GC III/6 first saw action against British aircraft on 8 June 1941, when they shot down three Fairey Fulmar
s, losing one D.520 with its pilot taken prisoner). Over the following days several escort missions were made to protect Martin, LeO and Bloch 200 (3/39 Esc) aircraft from British Royal Navy
fighters. On 9 June, Two Hurricanes were shot down (with another D.520 lost).
In total, during the Syria campaign 266 missions were flown by the Vichy French Air Force: 99 of them were made by D.520s, nine by MS.406s, 46 by Martin 167s and 31 by LeO 451s. The D.520s were therefore the most active of the French aircraft in the campaign, where they claimed 31 kills over British and Australian units while losing 11 of their own in air combat and a further 24 to AA fire, accidents and attacks on their airfields.. On 10 July, five D.520s attacked Bristol Blenheim
bombers from No. 45 Squadron RAF
that were being escorted by seven Curtiss Tomahawks from No. 3 Squadron RAAF
(3 Sqn). The French pilots claimed three Blenheims, but at least four of the D.520s were destroyed by the Australian escorts, including two by F/O
Peter Turnbull
. The following day, a Dewoitine pilot shot down a P-40 from 3 Sqn, the only Tomahawk lost during the campaign. This Dewoitine was in turn shot down by F/O Bobby Gibbes
. The initial advantage that the Vichy French Air Force enjoyed did not last long, and they lost most of their aircraft during the campaign. The majority of the lost aircraft were destroyed on the ground where the flat terrain, absence of infrastructure and absence of modern anti-aircraft (AA) artillery made them vulnerable to air attacks. On June 26, a strafing run by Tomahawks of 3 Sqn, on Homs airfield, destroyed five Dewoitine D.520s of Fighter Squadron II/3 (Groupe de Chasse II/3) and damaged six more.
By the end of the campaign, the Vichy forces had lost 179 aircraft from the approximately 289 committed to the Levant. The remaining aircraft with the range to do so, evacuated to Rhodes. The known French losses of fighter aircraft were 26 in air combat and 45 in strafing and bombing actions. Allied forces lost 41 planes, 27 of those shot down by French fighters. During Operation Torch
, GC III/3 (previously known as GC I/3) was engaged in combat with the Allies over Oran
. Flotille 1F saw action versus the United States Navy
F4F Wildcat
squadron VF-41
(from the carrier), over Casablanca
. One D.520 was among 14 US victory claims, with the only Allied losses being due to ground and friendly fire. Other Dewoitine-equipped units in North Africa such as GC II/7 or GC II/3 did not to take part in the fighting. Overall, the known D.520 air strength in North Africa was 173 D.520s (143 combat ready) of GC II/3, III/3, III/6, II/7 and II/5, another 30 were in Senegal with GC II/6. The Navy had Esc 1AC and 2AC. Many D.520s were destroyed on the ground by Allied bombing. The French Air Force lost 56 aircraft, among them 13 D.520s. The Navy lost 19 D.520s aircraft. Among the 44 kills that the French scored overall, there was an entire squadron of nine Fairey Albacore, from the HMS Furious, all shot down by D.520s of GC III/3.
, Lebanon. These D.520s were flown by pilots of the Normandie-Niemen
unit before the unit was sent to the USSR, where they flew the Yakovlev Yak-1
that had many similarities with the D.520.
, and progressively replaced by Spitfires
and P-39s in combat units.
During the liberation of France, a few D.520s abandoned by the Germans were used by ad hoc units in ground attacks against the isolated German pockets of resistance on the Western coast.
, they captured 246 D.520s; additionally, a batch of 62 was completed under German occupation. The captured Dewoitines were to be delivered to the Axis Balkan Front, although some were used by the Luftwaffe for training purposes while 60 were transferred to Italy and 96, or 120, to Vozdushni Voiski, the Bulgarian Air Force, for use in combat.
But D.520s reached Bulgaria only in August 1943, as the Bulgarian fighter pilots were still training on the type at Nancy with JG 107. The following month, the first 48 Dewoitines were taken over in a ceremony on Karlovo
airfield. Two months later, on 24 November, the D.520s were used in combat, when 17 out of the 60 B-24s of 15th USAAF arrived in the Bulgarian sky to bomb the capital, Sofia
. Twenty four Dewoitines took off from Vrashdebna base (along with 16 Bf 109G-2s from Bojourishte) and attacked the bombers and the 35 escorting P-38s. The Bulgarian pilots claimed four American aircraft for the loss of one fighter, three more aircraft had to force land. American bombers attacked Sofia again, on 10 December 1943. That day, 31 B-24 Liberators escorted by P-38s, were intercepted by six Dewoitines of II/6th Fighter regiment from Vrashdebna and 16 D.520s of I/6th Fighter regiment from Karlov (along with 17 Bf 109G-2s). The Americans claimed 11 D.520s for the loss on only one P-38. Later records showed only one Dewoitine was lost during that air battle.
The Vozdushni Voiski D.520s were again up in force, to face the massive Allied air raid of 30 March 1944. To intercept the 450 bombers (B-17s, B-24s and Handley Page Halifaxs) escorted by 150 P-38s, the Bulgarians scrambled 28 Dewoitines from I./6th at Karlovo, six D.520s from II/6th at Vrashdebna (together with 39 Bf 109G-6s and even Avia 135s). At least ten Allied aircraft (eight bombers and two P-38s) where shot down, while Vozdushni Voiski lost five fighters and three pilots. Two more Bulgarian aircraft had to force land.
During the last Allied raid on Sofia, on 17 April, the II./6th fighter scrambled seven Dewoitines (plus 16 Bf 109s) against 350 B-17s and B-24s escorted by 100 P-51 Mustangs. Bulgarians pilots, that up to that time had encountered only P-38s, mistook the P-51s for their own Bf 109 and before they realized their mistake, seven Bf 109G-6s had been shot down. That day the Vozdushni Voiski suffered the heaviest losses since the beginning of the war: nine fighters shot down and three that had to crash land. Six pilots lost their lives.
By 28 September 1944, twenty days after Bulgaria joined the Allies, Dewoitines still equipped a Orlyak (Group) of 6th Fighter regiment: I Group had a total of 17 D.520s, five in repair and 12 operational, for its three Jato (Squadrons).
Numerous sources have mentioned use of the D.520 by the Romanian Air Force
, but no evidence has ever been provided. One source claims the so-called Romanian Dewoitines were, in fact, in transit to Bulgaria and only flew over Romania in order to get to their final destination. This seems the most reliable explanation, viewed against the numbers of Dewoitines actually available.
About 60 D.520s were acquired by Regia Aeronautica
. Italian pilots appreciated the aircraft's capabilities and Hispano-Suiza HS.404
cannon, at least by 1940–1941 standards. The first three D.520s were assigned to 2° Stormo based at the Torino-Caselle airfield, where they were used for the defence of Torino's industrial area. Other D.520s were captured in Montélimar
, Orange
, Istres
and Aix-en-Provence
.
At the beginning of 1943, the Italian ace Luigi Gorrini
ferried D.520s taken as prizes of war
to Italy to be used for defence. "I have collected several dozen Dewoitines from various French airfields and the Toulouse
factory", he recalled later. "At the time, when we were still flying the Macchi C.200
, it was a good, if not very good, machine. Compared to the Macchi 200, it was superior only in one point: its armament of the Hispano-Suiza HS 404 20 mm cannon.". Italian pilots liked the 20 mm gun, the modern cockpit, the excellent radio set and the easy recovery from a spin but they also complained about the weak undercarriage and the small ammunition drum capability; the ammunition was not available in quantities (the HS.404 wasn't compatible with Breda and Scotti 20 mm guns, so everything depended on France's depots). Some D.520s were delivered to 22rd Gruppo (359a Squadriglia), led by Major Vittorio Minguzzi. At that time, B-24s frequently bombed Naples, so an effective interceptor was badly needed, and D.520s were all that were available in early 1943. The 359a pilots used Dewoitines with some success, On 21 May 1943, Regia Aereonautica and the Luftwaffe agreed to exchange 39 Lioré et Olivier LeO 451
s, captured by Italians at the SNCASE factory in Ambérieu-en-Bugey
(Lyon
), with a stock of 30 D.520s. Subsequently, in spring-summer 1943, the Dewoitines were used by 161° Gruppo Autonomo, based in southern Italy with 163a Squadriglia in Grottaglie
, 162a Squadriglia in Crotone
and 164a Squadriglia in Reggio Calabria
.
On 31 July 1943, Regia Aeronautica had still 47 Dewoitines in service. After the armistice of 8 September 1943, three D.520s, previously in service with 24° Gruppo, were used by the air force of Repubblica Sociale Italiana for training.
fighter squadron; these were later replaced with seven D.520s, three of them being two-seaters.
D.521
D.522
D.523
D.524
D.525
D.530
D.790
D.550
D.551 & D.552
D.520 amélioré
D.520 Z
M.520 T
Specific markings were applied during the Vichy era, consisting of white outlined fuselage roundels with a white fuselage stripe, and from mid-1941 on, the infamous "slave's pajamas" with red and yellow stripes on the engine cowling and tail surfaces.
Bulgaria
Nazi Germany
Kingdom of Italy (Napoleonic)
Intended operators
Romanian Air Force
Dewoitine D.520 n°603
Dewoitine D.520 n°655
Dewoitine D.520 n°862
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
fighter aircraft
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...
that entered service in early 1940, shortly after the opening of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. Unlike the Morane-Saulnier M.S.406
Morane-Saulnier M.S.406
The M.S.406 was a French Armée de l'Air fighter aircraft built by Morane-Saulnier starting in 1938. Numerically it was France's most important fighter during the opening stages of World War II....
, which was at that time the Armée de l'Airs most numerous fighter, the Dewoitine D.520 came close to being a match for the latest German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
types, such as the Messerschmitt Bf 109
Messerschmitt Bf 109
The Messerschmitt Bf 109, often called Me 109, was a German World War II fighter aircraft designed by Willy Messerschmitt and Robert Lusser during the early to mid 1930s...
. It was slower than the Bf 109E but superior in manoeuvrability. Because of a delayed production cycle, only a small number were available for combat with the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
.
The D.520 was designed in response to a 1936 requirement from the Armée de l'Air for a fast, modern fighter with a good climbing speed and an armament centred around a 20 mm cannon. At the time the most powerful V 12
V12 engine
A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft....
liquid cooled engine available in France was the Hispano-Suiza 12Y
Hispano-Suiza 12Y
The Hispano-Suiza 12Y was a French aircraft engine in the pre-WWII era. Developed from the earlier, and somewhat smaller, 12X, the 12Y became the primary 1,000 hp class engine and was used in a number of famous aircraft, including the Morane-Saulnier M.S.406 and Dewoitine D.520...
, which was less powerful, but lighter, than contemporary engines such as the Rolls-Royce Merlin
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...
and Daimler-Benz DB 601
Daimler-Benz DB 601
|-See also:-Bibliography:* Mankau, Heinz and Peter Petrick. Messerschmitt Bf 110, Me 210, Me 410. Raumfahrt, Germany: Aviatic Verlag, 2001. ISBN 3-92550-562-8.* Neil Gregor Daimler-Benz in the Third Reich. Yale University Press, 1998-External links:...
. Other fighters were designed to meet the specifications but none of them entered service, or entered service in small numbers and too late to play a significant role during the Battle of France
Battle of France
In the Second World War, the Battle of France was the German invasion of France and the Low Countries, beginning on 10 May 1940, which ended the Phoney War. The battle consisted of two main operations. In the first, Fall Gelb , German armoured units pushed through the Ardennes, to cut off and...
.
Development
In response to a specification for a new fighter promulgated by the l'Air Ministry on 15 June 1936, the design of the D.520 started in September 1936, at the private design firm led by Émile DewoitineÉmile Dewoitine
Émile Dewoitine was a French aviation industrialist.- Prewar industrial activities :Born in Crépy-en-Laonnois, Émile Dewoitine entered the aviation industry by working at Latécoère during Word War I...
. The specifications called for a maximum speed of 500 km/h (310.7 mph) at 4000 m (13,123.4 ft), the ability to climb to 8000 m (26,246.7 ft) in less than fifteen minutes, with take-off and landing runs not exceeding 400 m (1,312.3 ft). The armament was to be two 7.5 mm (.295 in) machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
s and one 20 mm Hispano-Suiza HS.9 cannon
Oerlikon FF
The FF were a series of 20mm autocannon introduced by Oerlikon in the late 1920s. The name comes from the German term Flügel Fest, meaning wing mounted, fixed, being one of the first 20mm guns to be small and light enough to fit into a fighter aircraft's wing...
, or two HS.9 cannon. Dewoitine had been disappointed with the performance of his last design, the Dewoitine D.513, which was rejected by the Armée de l'Air in favour of the Morane-Saulnier M.S.406
Morane-Saulnier M.S.406
The M.S.406 was a French Armée de l'Air fighter aircraft built by Morane-Saulnier starting in 1938. Numerically it was France's most important fighter during the opening stages of World War II....
, and decided to respond to the specifications with a design using the latest construction techniques and the most powerful available engine, the new 660 kW (890 hp) Hispano-Suiza 12Y-21 liquid-cooled engine. The first design was rejected by the l'Air Ministry, which, after being impressed by the British Hawker Hurricane
Hawker Hurricane
The Hawker Hurricane is a British single-seat fighter aircraft that was designed and predominantly built by Hawker Aircraft Ltd for the Royal Air Force...
and Supermarine Spitfire
Supermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and many other Allied countries throughout the Second World War. The Spitfire continued to be used as a front line fighter and in secondary roles into the 1950s...
, then uprated the specifications to include a maximum speed requirement of 500 km/h (310.7 mph). In response, Dewoitine renamed the further development, the "D.520".
Other aircraft designed to the same specification included the Morane-Saulnier M.S.450, the Loire-Nieuport 60 (later C.A.O 200, and the Caudron-Renault C.770
Caudron C.714
-See also:-References:NotesBibliography* Belcarz, Bartłomiej. GC 1/145 in France 1940. Sandomierz, Poland/Redbourn, UK: Mushroom Model Publications, 2002. ISBN 83-917178-1-X....
, none of which either left the drawing board or entered service. Two other concurrent French designs, the Bloch MB.152.01 and Bloch MB.155.C1 series and the Arsenal VG.33 entered service in small numbers with the Armée de l'Air during the Battle of France
Battle of France
In the Second World War, the Battle of France was the German invasion of France and the Low Countries, beginning on 10 May 1940, which ended the Phoney War. The battle consisted of two main operations. In the first, Fall Gelb , German armoured units pushed through the Ardennes, to cut off and...
, but too late to play a significant role.
In March 1937 the firm was conglomerated into one of a number of design-and-manufacturing pools, in this case SNCAM
SNCAM
Société nationale des constructions aéronautiques du Midi was a state-owned French aircraft manufacturer. The company was formed following the resolution of the 1936 general strike of French heavy industry, when the government of Léon Blum introduced an act to nationalize the French war industry...
. Because of this and continued changes in the Armée de l'Air's manufacturing programmes, work on the design of the D.520 was suspended throughout much of 1937, and it was not until January 1938 that a small number of draughtsmen started work on the first detail drawings for the prototype
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
. This prototype, D.520-01, powered by a Hispano-Suiza 12Y-21 temporarily driving a fixed-pitch, two bladed wooden propeller, first flew on 2 October 1938, but only managed to reach 480 km/h (298.3 mph) in flight tests, and suffered from dangerously high engine temperatures. Most of the problem was judged to come from greater than expected drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
from the underwing radiator
Radiator (engine cooling)
Radiators are used for cooling internal combustion engines, mainly in automobiles but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plant or any similar use of such an engine....
s, which exhausted across the upper wing surface, and these were replaced with a single radiator unit housed under the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
in a streamlined fairing. After minor damage in a landing accident, further modifications included changing the engine to a newer -29 model and incorporating exhaust ejectors for added thrust, along with a three-blade variable pitch propeller. These changes were enough to allow the aircraft to reach its design speed, achieving 530 km/h (329.3 mph). The maximum diving speed was 825 km/h (512.6 mph).
The prototype was followed in 1939 by two examples: D.520-02 and 03, first flown on 9 January and 5 May 1939 respectively, featuring new sliding canopies, a larger tail unit, and longer Olaer manufactured undercarriage legs; they also omitted the Handley-Page slats
Leading edge slats
Slats are aerodynamic surfaces on the leading edge of the wings of fixed-wing aircraft which, when deployed, allow the wing to operate at a higher angle of attack. A higher coefficient of lift is produced as a result of angle of attack and speed, so by deploying slats an aircraft can fly at slower...
fitted to the outer wings on 01. These prototypes were armed with the 20 mm Hispano-Suiza HS.9 cannon in a moteur-canon mount in which the barrel was mounted in a sleeve between the cylinder banks and fired through the propeller spinner. and two MAC 1934
MAC 1934
In 1934 the Manufacture d'Armes de Châtellerault completed the development of the MAC 1934 machine gun to replace the Darne mod. 1933 machine gun aboard aircraft of the Armée de l'Air...
7.5 mm (.295 in) machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
s, each initially with 300 rounds per gun, housed in small pods under the wing. The third prototype also introduced a small tailwheel instead of the original skid. The second prototype was later fitted with a Hispano-Suiza 12Y-31 engine and achieved a maximum speed of 550 km/h (341.8 mph) and reached 8000 m (26,246.7 ft) in 12 minutes 53 seconds. Flight tests proceeded successfully, resulting in a contract issued in March 1939 for 200 production machines to be powered by the newer -31 engine (later replaced by the -45). A contract for an additional 600 aircraft was issued in June, albeit reduced to 510 in July 1939.
With the outbreak of war, a new contract brought the total of D.520s on order to 1,280, with the production rate to be 200 aircraft per month from May 1940. The Aéronautique Navale
Aviation Navale
French Naval Aviation of the French Navy includes 206 aircraft and 6,800 men, both civilians and military personnel. They operate from six airbases, five of them in Metropolitan France and one overseas....
then ordered 120. Another Armée de l'air order in April 1940 brought the total to 2,250 and increased production quotas to 350 a month.
The first production D.520 flew in October 1939. On production aircraft, the rear fuselage was extended by 51 cm (20.1 in), the engine cowling panels were redesigned, the curved, one-piece windshield was replaced by one containing an optically flat panel and armour plate was fitted behind the pilot's seat. Most production examples were powered by the 935 CV Hispano-Suiza 12Y-45 with the new Szydlowski
Joseph Szydlowski
Joseph Szydlowski , was a Jewish-Polish-French-Israeli aircraft engine designer who founded Turbomeca in France.- Biography and career :...
-Planiol supercharger
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
, although later production versions used the 960 CV Hispano-Suiza 12Y-49. The production standard armament was a 20 mm HS.404 cannon firing through the propeller hub and four belt-fed MAC 1934 M39 7.5 mm (.295 in) machine guns in the wings.
As the first batch of D.520s rolled off the production lines, they failed acceptance tests due to insufficient top speed and troublesome cooling. Redesigned compressor intakes, a modified cooling circuit and propulsive exhaust pipes proved to be effective remedies for these shortcomings, but as early examples had to be retrofitted with these improvements, the type was not declared combat ready until April 1940.
Design
An all-metal structure was used, except for fabric-covered ailerons and tail surfaces. The wing, even if single-spar, was a solid and rigid unit with a secondary spar and many reinforced parts. The inwardly retracting undercarriage had a wide 2.83 m (9.3 ft) track, and was fitted with wide, low pressure tyres. A self-sealing fuel tank with a capacity of 396 l (87 imp gal) was mounted between the engine and cockpit, along with two wing tanks which, combined, carried another 240 l (53 imp gal), for a total of 636 (131 imp gall); this was considerably more than the contemporary Bf 109E, Spitfire I and early Italian fighters, each with about 400 l (88 imp gal) fuel capacity. The ferry range was from 1300 km (807.8 mi) to 1500 km (932.1 mi) at 450 km/h (279.6 mph) which, from June 1940, allowed D.520s to escape to North Africa when France fell. The handling changed according to the amount of fuel carried; using the fuselage tank alone fuel consumption had no appreciable affect on handling because the tank was on the centre of gravity, but, with full wing tanks, directional control was compromised, especially in a dive. The flight controls were well harmonized and the aircraft was easy to control at high speed. The maximum dive speed tested was 830 km/h (515.7 mph) with no buffeting and excellent stability both in the dive (depending on fuel load) and as a gun platform.The Hispano-Suiza 12Y-45 engine was an underpowered, older design, with 850 CV at takeoff at 2,400 rpm, or 935 CV emergency power at 2,520 rpm and at a height of 1900 m (6,233.6 ft). The Hispano engine had some advantages over some later engines; for example, the weight was only 515 kg (1,135.4 lb), compared to the 620 kg (1,366.9 lb) of the Rolls-Royce Merlin III. Fuel was fed via six Solex
Solex
Solex was a French manufacturer of carburetors and the powered bicycle VéloSoleX.The Solex company was founded by Marcel Mennesson and Maurice Goudard to manufacture vehicle radiators...
S.V. 56 carbureteurs mounted on an inlet manifold which directed compressed air from the supercharger to the engine cylinders; the 12Y-45 and -49s fitted to production D.520s used either 92 or 100 octane
Octane rating
Octane rating or octane number is a standard measure of the anti-knock properties of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand before detonating...
fuel. The -45 drove an electrically operated Ratier Type 1606M three-bladed, 3 m (9.8 ft) diameter, variable pitch propeller, while D.520s from № 351 were fitted with the 12Y-49 960 CV engine driving a Chauvière type 3918 pneumatically operated propeller, also 3 m (9.8 ft) in diameter.
The D.520 had a fire suppression system with a fire extinguisher activated from the cockpit. The engine was started by a simple but effective system, operating with compressed air. A Viet 250 air compressor charged several air bottles (one with 12 l capacity, as well as another 8 l tank, three smaller 1 l units matched to the weapons). The 12 l air bottle was used for the brakes and later, for the Chauvière propeller's constant speed adjustment. The small air bottles provided up to 12 seconds at 9000 m (29,527.6 ft) or 20 seconds pressure at low level, before the Viet air compressor re-charged them. The pilot had a complete set of cockpit instruments, and a 10 l oxygen bottle located in the fuselage just behind his seat, with either Munerelle or Gourdou oxygen regulator systems mounted on the right instrument panel. Equipment included a Radio Industrie Type Rl 537 radio-receiver set, an OPL RX 39 reflector sight
Reflector sight
A reflector or reflex sight is a generally non-magnifying optical device that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view...
(less effective than the Revi system), a height adjustable seat, and a sliding canopy with large, clear panels. Except over the long nose, the pilot's view was good, since the pilot was seated quite high over the forward fuselage, however, no rear-facing mirrors were fitted.
Production-standard armament consisted of a 20 mm HS.404 moteur-canon, with an ammunition capacity of 60 rounds, firing through the propeller hub, and four belt-fed MAC 1934 M39 7.5 mm (.295 in) machine guns in the wings, each with 675 rounds per gun. The MAC 1934 machine guns had a high rate of fire
Rate of fire
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. It is usually measured in rounds per minute , or per second .-Overview:...
of 1,200 rounds per minute (rpm), while the effective HS.404 fired at 600 rpm and was accurate up to 500 m (1,640.4 ft); the ammunition capacity meant that the MAC 1934s could be fired for a total of 30 seconds, while the HS. 404 had 10 seconds worth of ammunition. In combat the MS.406 had only two 7.5 mm and was, therefore, at a disadvantage when the HS.404 had used up its ammunition, while a D.520 could continue to fight effectively because it had four fast-firing machine guns (over 80 rounds/sec), with 20+ seconds of ammunition still available. The D.520 had provisions for two BE33 "illuminating bombs", useful for nocturnal interception missions, but these were rarely used because French fighters rarely flew night-time missions.
The D.520 was designed to be maintained easily with many inspection panels, a rare feature for its time. Re-charging the D.520 ammunition was swift and easy; the machine gun magazines required five minutes each and three minutes for the 20 mm cannon. To fill the machine gun ammunition boxes took 15 minutes, while five minutes were needed to empty the 20 mm box (the cartridges were not expelled). The D.520's cockpit was set well back in the fuselage, aft of the trailing edge. That gave the pilot good downward visibility, but the long nose in front of him was a drawback when taxiing on the ground.
Production was optimized with a reduced 7,000 man/hour each, roughly half the time compared to the previous D.510 and MS.406, and far less many other fighters of the time, such as the MC.200/202 (21,000 hours), but around 50% more than a Bf 109E (4,500 hours). The French Air Ministry planned for over 300 aircraft/month and managed to reach this goal, especially in June 1940, but it was too late to affect the tide of battle.
After the armistice with Germany, a further 180 machines were built, bringing the production total to 905.
Although employing a modern design philosophy for its time, the D.520 was considered more difficult to fly than the older MS.406. Capt. Eric Brown, commanding officer of the RAF's Captured Enemy Aircraft Flight, tested the D.520 at RAE Farnborough, saying that “It was a nasty little brute. Looked beautiful but didn’t fly beautifully. Once you get it on the ground, I was told not to leave the controls until it was in the hangar and the engine stopped. You could be taxiing toward the hangar and sit back when suddenly it would go in a right angle.”
Battle of France
The Groupe de Chasse I/3Groupe de Chasse I/3
Groupe de Chasse I/3 was a fighter squadron of the French Air Force during World War II.At the outbreak of World War II, GC I/3 was equipped with the Morane-Saulnier MS.406. After seeing combat during the Phoney War, GC I/3 relocated to southern France. While at Cannes-Mandelieu, the unit converted...
was the first unit to get the D.520, receiving its first aircraft in January 1940. These were unarmed and used for pilot training. In April and May 1940, operational units received 34 production D.520s; the type proving to be very popular with the pilots. In comparative trials on 21 April 1940 at CEMA at Orleans-Bricy against a captured Bf 109E-3, the German aircraft had a 32 km/h (20 mph) speed advantage owing to its more powerful engine. However, the D.520 had superior maneuverability, matching its turning circle, although displaying nasty characteristics when departing and spinning out of the turn repeatedly during the tests. The Bf 109, owing to its slats
Leading edge slats
Slats are aerodynamic surfaces on the leading edge of the wings of fixed-wing aircraft which, when deployed, allow the wing to operate at a higher angle of attack. A higher coefficient of lift is produced as a result of angle of attack and speed, so by deploying slats an aircraft can fly at slower...
, could easily sustain the turn on the edge of a stall.
By 10 May 1940, when Germany invaded France and the Low Countries, 228 D.520s had been manufactured, but the Armée de l'Air had only accepted 75, as most others had been sent back to the factory to be retrofitted to the new standard. As a result, only GC I/3 was fully equipped, having 36 aircraft. They met the Luftwaffe on 13 May, shooting down three Henschel Hs 126
Henschel Hs 126
|-See also:-References:NotesBibliography* Green, William. Warplanes of the Third Reich. London: Macdonald and Jane's Publishers Ltd., 1970 . ISBN 0-356-02382-6....
s and one Heinkel He 111
Heinkel He 111
The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a "Wolf in sheep's clothing", it masqueraded as a transport aircraft, but its purpose was to provide the Luftwaffe with a fast medium...
without loss. Four more Groupes de Chasse and three naval Escadrilles rearmed with the type before France's surrender. GC II/3, GC III/3, GC III/6 and GC II/7 later completed conversion on the D.520. A naval unit, the 1er Flotille de Chasse, was also equipped with the Dewoitine. But only GC I/3, II/7, II/6 and the naval AC 1 saw any action in the Battle of France
Battle of France
In the Second World War, the Battle of France was the German invasion of France and the Low Countries, beginning on 10 May 1940, which ended the Phoney War. The battle consisted of two main operations. In the first, Fall Gelb , German armoured units pushed through the Ardennes, to cut off and...
. GC III/7 converted to the D.520 too late to be involved in combat.
In air combat, mostly against Italians, the Dewoitine 520s claimed 114 air victories, plus 39 probables. Eighty five D.520s were lost. By the armistice at the end of June 1940, 437 D.520s had been built with 351 delivered.
After the armistice, 165 D.520s were evacuated to North Africa. GC I/3, II/3, III/3, III/6 and II/7 flew their aircraft to Algeria to avoid capture. Three more, from GC III/7, escaped to Britain and were delivered to the Free French. A total of 153 D.520s remained in mainland France.
One of the most successful D.520 pilots was Pierre Le Gloan
Pierre Le Gloan
Pierre Le Gloan , French pilot of World War II.He was born in Brittany, France. At the age of eighteen he joined the French Air Force. At the outbreak of the war he served in the GC III/6 fighter squadron, flying the Morane-Saulnier MS.406...
, who shot down 18 aircraft (four Germans, seven Italian and seven British), scoring all of his kills with the D.520, and ranked as the fourth-highest French ace of the war.
Under Vichy
In April 1941, the German armistice commission authorized VichyVichy France
Vichy France, Vichy Regime, or Vichy Government, are common terms used to describe the government of France that collaborated with the Axis powers from July 1940 to August 1944. This government succeeded the Third Republic and preceded the Provisional Government of the French Republic...
authorities to resume production of a batch of 1,000 military aircraft for their own use, under the condition that 2,000 German-designed aircraft would later be manufactured in France and delivered to Germany. As part of this agreement, 550 examples of the D.520 were ordered to replace all other single-seat fighters in service. The plan was to have the Dewoitine eventually equip a total of 17 Groupes with 442 aircraft, three escadrilles of the Aéronautique navale with 37 aircraft each, plus three training units with 13 aircraft. The agreement stated that aircraft of this new batch were to be similar to the ones already in service. . From serial number 543 on, however, D.520s used the 12Y-49 engine that had a slightly higher rated performance than the 12Y-45, although the German Armistice Commission
German Armistice Commission
The German Armistice Commission was created by Article Twenty-Two of the Armistice Agreement between the German High Command of the Armed Forces and French Plenipottentiaries, Compiègne, June 22, 1940.-Description:...
explicitly prohibited replacing the original engines with the more powerful 12Y51 or 12Z engines.
In 1941, D.520s of GC III/6, II/3 and naval escadrille 1AC fought the Allies during the Syria-Lebanon campaign
Syria-Lebanon campaign
The Syria–Lebanon campaign, also known as Operation Exporter, was the Allied invasion of Vichy French-controlled Syria and Lebanon, in June–July 1941, during World War II. Time Magazine referred to the fighting as a "mixed show" while it was taking place and the campaign remains little known, even...
. The Vichy French Air Force
Vichy French Air Force
The Vichy French Air Force was the aerial branch of the armed forces of Vichy France - the government of France that collaborated with the Axis powers following the defeat of France by Germany in 1940....
(Armée de l'Air de Vichy) was already relatively strong, but several units were sent to reinforce it. D.520s were the only French single-seat fighters capable of making the trip to Syria. The GC III/6 was sent first. The ferry trip was very difficult for a 1940 interceptor and the pilots pushed their planes as far as their fuel tanks would allow them to. They flew from France to Syria with intermediate stops at Rome, Brindisi or Catania. Another route was available through Germany and Greece (Athens), but it was seldom used. The trip always included a stopover in Rhodes (once an Italian base), before the final flight to Syria. This meant several thousands of kilometers were flown over mountains and sea. The most demanding part was Catania-Rhodes, which entailed no less than 1,200 km flown over the sea. Even the trip from Rhodes to Syria was 800 km. LeO 451s and Martin 167F bombers had few problems, but D.520s were forced to fly a strenuous and dangerous mission, without any help or external assistance. Of the 168 French aircraft (of all types) sent to Syria, 155 accomplished their mission and successfully arrived. The Vichy Air force was numerically strong, but with very few ground crew and spare parts, so the operational flying time for the D.520s was very limited. D.520s of GC III/6 first saw action against British aircraft on 8 June 1941, when they shot down three Fairey Fulmar
Fairey Fulmar
The Fairey Fulmar was a British carrier-borne fighter aircraft that served with the Fleet Air Arm during the Second World War. A total of 600 were built by Fairey Aviation at its Stockport factory between January 1940 and December 1942...
s, losing one D.520 with its pilot taken prisoner). Over the following days several escort missions were made to protect Martin, LeO and Bloch 200 (3/39 Esc) aircraft from British Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
fighters. On 9 June, Two Hurricanes were shot down (with another D.520 lost).
In total, during the Syria campaign 266 missions were flown by the Vichy French Air Force: 99 of them were made by D.520s, nine by MS.406s, 46 by Martin 167s and 31 by LeO 451s. The D.520s were therefore the most active of the French aircraft in the campaign, where they claimed 31 kills over British and Australian units while losing 11 of their own in air combat and a further 24 to AA fire, accidents and attacks on their airfields.. On 10 July, five D.520s attacked Bristol Blenheim
Bristol Blenheim
The Bristol Blenheim was a British light bomber aircraft designed and built by the Bristol Aeroplane Company that was used extensively in the early days of the Second World War. It was adapted as an interim long-range and night fighter, pending the availability of the Beaufighter...
bombers from No. 45 Squadron RAF
No. 45 Squadron RAF
-First World War:Formed during World War I at Gosport on 1 March 1916 as Number 45 Squadron, the unit was first equipped with Sopwith 1½ Strutters which it was to fly in the Scout role. Deployed to France in October of that year, the Squadron found itself suffering heavy losses due to the quality...
that were being escorted by seven Curtiss Tomahawks from No. 3 Squadron RAAF
No. 3 Squadron RAAF
No. 3 Squadron is a Royal Australian Air Force fighter squadron. It was first formed in 1916 and currently operates F/A-18 Hornet aircraft from RAAF Base Williamtown, near Newcastle, New South Wales.-World War I:...
(3 Sqn). The French pilots claimed three Blenheims, but at least four of the D.520s were destroyed by the Australian escorts, including two by F/O
Flying Officer
Flying officer is a junior commissioned rank in the Royal Air Force and the air forces of many countries which have historical British influence...
Peter Turnbull
Peter Turnbull (RAAF officer)
Peter St George Bruce Turnbull DFC was an Australian fighter ace of World War II, credited with twelve aerial victories. Born in Armidale, New South Wales, he was an electrician before he joined the Royal Australian Air Force in January 1939...
. The following day, a Dewoitine pilot shot down a P-40 from 3 Sqn, the only Tomahawk lost during the campaign. This Dewoitine was in turn shot down by F/O Bobby Gibbes
Bobby Gibbes
Robert Henry Maxwell Gibbes DSO, DFC & Bar, OAM was a leading Australian fighter ace of World War II. He was officially credited with shooting down 10¼ enemy aircraft, although his score is often reported as 12 destroyed...
. The initial advantage that the Vichy French Air Force enjoyed did not last long, and they lost most of their aircraft during the campaign. The majority of the lost aircraft were destroyed on the ground where the flat terrain, absence of infrastructure and absence of modern anti-aircraft (AA) artillery made them vulnerable to air attacks. On June 26, a strafing run by Tomahawks of 3 Sqn, on Homs airfield, destroyed five Dewoitine D.520s of Fighter Squadron II/3 (Groupe de Chasse II/3) and damaged six more.
By the end of the campaign, the Vichy forces had lost 179 aircraft from the approximately 289 committed to the Levant. The remaining aircraft with the range to do so, evacuated to Rhodes. The known French losses of fighter aircraft were 26 in air combat and 45 in strafing and bombing actions. Allied forces lost 41 planes, 27 of those shot down by French fighters. During Operation Torch
Operation Torch
Operation Torch was the British-American invasion of French North Africa in World War II during the North African Campaign, started on 8 November 1942....
, GC III/3 (previously known as GC I/3) was engaged in combat with the Allies over Oran
Oran
Oran is a major city on the northwestern Mediterranean coast of Algeria, and the second largest city of the country.It is the capital of the Oran Province . The city has a population of 759,645 , while the metropolitan area has a population of approximately 1,500,000, making it the second largest...
. Flotille 1F saw action versus the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
F4F Wildcat
F4F Wildcat
The Grumman F4F Wildcat was an American carrier-based fighter aircraft that began service with both the United States Navy and the British Royal Navy in 1940...
squadron VF-41
VFA-11
Strike Fighter Squadron 11 , also known as the "Red Rippers", are a United States Navy fighter squadron stationed at Naval Air Station Oceana, Virginia Beach, VA...
(from the carrier), over Casablanca
Casablanca
Casablanca is a city in western Morocco, located on the Atlantic Ocean. It is the capital of the Grand Casablanca region.Casablanca is Morocco's largest city as well as its chief port. It is also the biggest city in the Maghreb. The 2004 census recorded a population of 2,949,805 in the prefecture...
. One D.520 was among 14 US victory claims, with the only Allied losses being due to ground and friendly fire. Other Dewoitine-equipped units in North Africa such as GC II/7 or GC II/3 did not to take part in the fighting. Overall, the known D.520 air strength in North Africa was 173 D.520s (143 combat ready) of GC II/3, III/3, III/6, II/7 and II/5, another 30 were in Senegal with GC II/6. The Navy had Esc 1AC and 2AC. Many D.520s were destroyed on the ground by Allied bombing. The French Air Force lost 56 aircraft, among them 13 D.520s. The Navy lost 19 D.520s aircraft. Among the 44 kills that the French scored overall, there was an entire squadron of nine Fairey Albacore, from the HMS Furious, all shot down by D.520s of GC III/3.
Free French Dewoitines
A very small number of D.520s were briefly operated by Free French Forces for training purposes. Along with the three examples that had flown to Britain in June 1940, two other D.520s were recovered from retreating Vichy forces in RayakRayak (Riyaq)
Riyaq , also Rayak, is a Lebanese town in the Beqaa Mohafazat , near the city of Zahlé. It has one military airport, an old train station on the former line from Beirut to Damascus, and a hospital....
, Lebanon. These D.520s were flown by pilots of the Normandie-Niemen
Normandie-Niemen
The Normandie-Niemen Regiment was a fighter squadron, later regiment of the French Air Force. It served on the Eastern Front of the European Theatre of World War II with the 1st Air Army...
unit before the unit was sent to the USSR, where they flew the Yakovlev Yak-1
Yakovlev Yak-1
The Yakovlev Yak-1 was a World War II Soviet fighter aircraft. Produced from early 1940, it was a single-seat monoplane with a composite structure and wooden wings....
that had many similarities with the D.520.
With the Allies
In December 1942, as French forces formerly under Vichy sided with the Allies, there were 153 D.520s left in French hands in North Africa. They flew a few patrols during the Battle of Tunisia, but were considered obsolete, and their radio sets were incompatible with Allied equipment. From early 1943 on, they were relegated to training duties at the fighter school in MeknesMeknes
Meknes is a city in northern Morocco, located from the capital Rabat and from Fes. It is served by the A2 expressway between those two cities and by the corresponding railway. Meknes was the capital of Morocco under the reign of Moulay Ismail , before it was relocated to Marrakech. The...
, and progressively replaced by Spitfires
Supermarine Spitfire
The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and many other Allied countries throughout the Second World War. The Spitfire continued to be used as a front line fighter and in secondary roles into the 1950s...
and P-39s in combat units.
During the liberation of France, a few D.520s abandoned by the Germans were used by ad hoc units in ground attacks against the isolated German pockets of resistance on the Western coast.
Foreign users
As German forces invaded Vichy's so-called "free zone" in November 1942Case Anton
Operation Anton was the codename for the military occupation of Vichy France carried out by Germany and Italy in November 1942.- Background :...
, they captured 246 D.520s; additionally, a batch of 62 was completed under German occupation. The captured Dewoitines were to be delivered to the Axis Balkan Front, although some were used by the Luftwaffe for training purposes while 60 were transferred to Italy and 96, or 120, to Vozdushni Voiski, the Bulgarian Air Force, for use in combat.
But D.520s reached Bulgaria only in August 1943, as the Bulgarian fighter pilots were still training on the type at Nancy with JG 107. The following month, the first 48 Dewoitines were taken over in a ceremony on Karlovo
Karlovo
Karlovo is a picturesque and a historically important town in central Bulgaria located in a fertile valley along the river Stryama at the southern foot of the Balkan Mountains...
airfield. Two months later, on 24 November, the D.520s were used in combat, when 17 out of the 60 B-24s of 15th USAAF arrived in the Bulgarian sky to bomb the capital, Sofia
Sofia
Sofia is the capital and largest city of Bulgaria and the 12th largest city in the European Union with a population of 1.27 million people. It is located in western Bulgaria, at the foot of Mount Vitosha and approximately at the centre of the Balkan Peninsula.Prehistoric settlements were excavated...
. Twenty four Dewoitines took off from Vrashdebna base (along with 16 Bf 109G-2s from Bojourishte) and attacked the bombers and the 35 escorting P-38s. The Bulgarian pilots claimed four American aircraft for the loss of one fighter, three more aircraft had to force land. American bombers attacked Sofia again, on 10 December 1943. That day, 31 B-24 Liberators escorted by P-38s, were intercepted by six Dewoitines of II/6th Fighter regiment from Vrashdebna and 16 D.520s of I/6th Fighter regiment from Karlov (along with 17 Bf 109G-2s). The Americans claimed 11 D.520s for the loss on only one P-38. Later records showed only one Dewoitine was lost during that air battle.
The Vozdushni Voiski D.520s were again up in force, to face the massive Allied air raid of 30 March 1944. To intercept the 450 bombers (B-17s, B-24s and Handley Page Halifaxs) escorted by 150 P-38s, the Bulgarians scrambled 28 Dewoitines from I./6th at Karlovo, six D.520s from II/6th at Vrashdebna (together with 39 Bf 109G-6s and even Avia 135s). At least ten Allied aircraft (eight bombers and two P-38s) where shot down, while Vozdushni Voiski lost five fighters and three pilots. Two more Bulgarian aircraft had to force land.
During the last Allied raid on Sofia, on 17 April, the II./6th fighter scrambled seven Dewoitines (plus 16 Bf 109s) against 350 B-17s and B-24s escorted by 100 P-51 Mustangs. Bulgarians pilots, that up to that time had encountered only P-38s, mistook the P-51s for their own Bf 109 and before they realized their mistake, seven Bf 109G-6s had been shot down. That day the Vozdushni Voiski suffered the heaviest losses since the beginning of the war: nine fighters shot down and three that had to crash land. Six pilots lost their lives.
By 28 September 1944, twenty days after Bulgaria joined the Allies, Dewoitines still equipped a Orlyak (Group) of 6th Fighter regiment: I Group had a total of 17 D.520s, five in repair and 12 operational, for its three Jato (Squadrons).
Numerous sources have mentioned use of the D.520 by the Romanian Air Force
Romanian Air Force
The Romanian Air Force is the air force branch of the Romanian Armed Forces. It has an air force headquarters, an operational command, four air bases and an air defense brigade...
, but no evidence has ever been provided. One source claims the so-called Romanian Dewoitines were, in fact, in transit to Bulgaria and only flew over Romania in order to get to their final destination. This seems the most reliable explanation, viewed against the numbers of Dewoitines actually available.
About 60 D.520s were acquired by Regia Aeronautica
Regia Aeronautica
The Italian Royal Air Force was the name of the air force of the Kingdom of Italy. It was established as a service independent of the Royal Italian Army from 1923 until 1946...
. Italian pilots appreciated the aircraft's capabilities and Hispano-Suiza HS.404
Hispano-Suiza HS.404
The Hispano-Suiza HS.404 was an autocannon widely used as both an aircraft and land weapon in the 20th century by British, American, French, and numerous other military services. The cannon is also referred to as Birkigt type 404, after its designer. Firing a 20 mm caliber projectile, it delivered...
cannon, at least by 1940–1941 standards. The first three D.520s were assigned to 2° Stormo based at the Torino-Caselle airfield, where they were used for the defence of Torino's industrial area. Other D.520s were captured in Montélimar
Montélimar
Montélimar is a commune in the Drôme department in southeastern France. It is the second-largest town in the department after Valence.-History:...
, Orange
Orange, Vaucluse
Orange is a commune in the Vaucluse department in the Provence-Alpes-Côte d'Azur region in southeastern France.It has a primarily agricultural economy...
, Istres
Istres
Istres is a commune in southern France, some 60 km northwest of Marseille. It is in the Provence-Alpes-Côte d'Azur region, in the Bouches-du-Rhône department, of which it is a subprefecture...
and Aix-en-Provence
Aix-en-Provence
Aix , or Aix-en-Provence to distinguish it from other cities built over hot springs, is a city-commune in southern France, some north of Marseille. It is in the region of Provence-Alpes-Côte d'Azur, in the département of Bouches-du-Rhône, of which it is a subprefecture. The population of Aix is...
.
At the beginning of 1943, the Italian ace Luigi Gorrini
Luigi Gorrini
Luigi Gorrini, MOVM, is a former Italian World War II fighter pilot in the Regia Aeronautica and in the Aeronautica Nazionale Repubblicana....
ferried D.520s taken as prizes of war
Prize of war
A prize of war is a piece of military property seized by the victorious party after a war or battle, typically at sea. This term was used nearly exclusively in terms of a captured ship during the 18th and 19th centuries....
to Italy to be used for defence. "I have collected several dozen Dewoitines from various French airfields and the Toulouse
Toulouse
Toulouse is a city in the Haute-Garonne department in southwestern FranceIt lies on the banks of the River Garonne, 590 km away from Paris and half-way between the Atlantic Ocean and the Mediterranean Sea...
factory", he recalled later. "At the time, when we were still flying the Macchi C.200
Macchi C.200
The Macchi C.200 Saetta was a World War II fighter aircraft built by Aeronautica Macchi in Italy, and used in various forms throughout the Regia Aeronautica . The MC.200 had excellent manoeuvrability and general flying characteristics left little to be desired...
, it was a good, if not very good, machine. Compared to the Macchi 200, it was superior only in one point: its armament of the Hispano-Suiza HS 404 20 mm cannon.". Italian pilots liked the 20 mm gun, the modern cockpit, the excellent radio set and the easy recovery from a spin but they also complained about the weak undercarriage and the small ammunition drum capability; the ammunition was not available in quantities (the HS.404 wasn't compatible with Breda and Scotti 20 mm guns, so everything depended on France's depots). Some D.520s were delivered to 22rd Gruppo (359a Squadriglia), led by Major Vittorio Minguzzi. At that time, B-24s frequently bombed Naples, so an effective interceptor was badly needed, and D.520s were all that were available in early 1943. The 359a pilots used Dewoitines with some success, On 21 May 1943, Regia Aereonautica and the Luftwaffe agreed to exchange 39 Lioré et Olivier LeO 451
Lioré et Olivier LeO 451
Lioré-et-Olivier LeO 45 was a French medium bomber used during World War II. It was a low-wing monoplane, all metal in construction, equipped with a retractable undercarriage and powered by two 1,100 hp Hispano-Suiza engines. It was a very effective bomber, but it appeared too late to give any...
s, captured by Italians at the SNCASE factory in Ambérieu-en-Bugey
Ambérieu-en-Bugey
Ambérieu-en-Bugey is a commune in the department of Ain in eastern France.It is the largest town in the arrondissement of Belley and the seat of the Ambérieu-en-Bugey canton, as well as the capital of the historic region of Bugey.-Geography:...
(Lyon
Lyon
Lyon , is a city in east-central France in the Rhône-Alpes region, situated between Paris and Marseille. Lyon is located at from Paris, from Marseille, from Geneva, from Turin, and from Barcelona. The residents of the city are called Lyonnais....
), with a stock of 30 D.520s. Subsequently, in spring-summer 1943, the Dewoitines were used by 161° Gruppo Autonomo, based in southern Italy with 163a Squadriglia in Grottaglie
Grottaglie
Grottaglie is a town and comune in the province of Taranto, Puglia, southern Italy.-Geography:Grottaglie is located in the Salento peninsula, a whole rock of limestone dividing Adriatic sea from Ionian sea. The countryside around the city is scattered with vast and deep ravines that open the ground...
, 162a Squadriglia in Crotone
Crotone
Crotone is a city and comune in Calabria, southern Italy, on the Ionian Sea. Founded circa 710 BC as the Achaean colony of Croton , it was known as Cotrone from the Middle Ages until 1928, when its name was changed to the current one. In 1994 it became the capital of the newly established...
and 164a Squadriglia in Reggio Calabria
Reggio Calabria
Reggio di Calabria , commonly known as Reggio Calabria or Reggio, is the biggest city and the most populated comune of Calabria, southern Italy, and is the capital of the Province of Reggio Calabria and seat of the Council of Calabrian government.Reggio is located on the "toe" of the Italian...
.
On 31 July 1943, Regia Aeronautica had still 47 Dewoitines in service. After the armistice of 8 September 1943, three D.520s, previously in service with 24° Gruppo, were used by the air force of Repubblica Sociale Italiana for training.
Postwar service
After the war, the D.520s that remained in France were used as trainers. One example was field-modified as a two-seater in late 1945. In March 1946, after further experiments, the Armée de l'air ordered a further batch of 20 D.520s to be converted; however, only 13 of these D.520 DC conversions were completed. The last flight of an operational D.520 was made on 3 September 1953 with EPAA (Esquadrille de Presentation de l'Armée de l'Air). Initially this unit had flown Yak-3s, formally of the Normandie-NiemenNormandie-Niemen
The Normandie-Niemen Regiment was a fighter squadron, later regiment of the French Air Force. It served on the Eastern Front of the European Theatre of World War II with the 1st Air Army...
fighter squadron; these were later replaced with seven D.520s, three of them being two-seaters.
Variants
D.520- Main production version, sometimes designated D.520 S (for série – production) or D.520 C1 (for chasseur – fighter, single-seat).
Direct derivatives
In 1940, SNCAM had several projects to fit the D.520 airframe with more powerful engines. These developments were halted by the June armistice.D.521
- engine replaced by a Rolls-Royce Merlin III, one example built, project cancelled.
D.522
- engine replaced by a Allison V-1710 C-1, project abandoned after the armistice (22 June 1940).
D.523
- engine replaced by slightly different sub-variants of the 820 kW (1,100 hp) Hispano-Suiza 12Y-51, with Szydlowski-Planiol superchargerSuperchargerA supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
. D.523 Prototype was completing pre-production trials in June 1940.
D.524
- Version powered by Hispano-Suiza 12Y-89ter engine. One prototype built, never flew.
D.525
- development version of the D.523
D.530
- planned version with a 1,044 kW (1,400 hp) Rolls-Royce MerlinRolls-Royce MerlinThe Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...
or a 1,342 kW (1,800 hp) Hispano-Suiza 12Y.
Related pre-war projects
HD.780- Seaplane derivative of the D.520, one prototype built, never flew, development cancelled with the armistice.
D.790
- Carrier-borne derivative project, none built.
D.550
- Unarmed aircraft built for speed record attempt, with airframe loosely based on the D.520 but using weight-saving construction techniques. One example built.
D.551 & D.552
- Military developments of the D.550. 12 examples built, none flew. Development was resumed in 1941, but quickly terminated by the Germans.
Post-armistice developments
Several projects were initiated after the June 1940 armistice. They all were terminated with the German occupation of Southern France in November 1942.D.520 amélioré
- Single production D.520 experimentally fitted with minor improvements so as to improve top speed with unchanged engine.
D.520 Z
- D.520 airframe with 12Z engine and minor improvements. One example built. Development resumed after the war (as SE.520Z), but eventually cancelled in 1949.
M.520 T
- Different airframe loosely based on the D.520. None built.
Postwar derivative
D.520 DC (double commande – dual control)- Two-seater trainer conversion, at least 13 built.
Markings
Apart from the first prototype and postwar examples, D.520s sported the usual French camouflage of dark blue-grey, khaki, and dark brown with light blue-grey undersurfaces. The camouflage pattern was not standardized. The national markings were the standard light blue-white-red roundels on the wingtips, as well as on the rear fuselage, and the rudder flag.Specific markings were applied during the Vichy era, consisting of white outlined fuselage roundels with a white fuselage stripe, and from mid-1941 on, the infamous "slave's pajamas" with red and yellow stripes on the engine cowling and tail surfaces.
Operators
Main operators BulgariaHistory of Independent Bulgaria
The Treaty of San Stefano of March 3, 1878 provided for a self-governing Bulgarian state, which comprised the geographical regions of Moesia, Thrace and Macedonia. Based on that date Bulgarians celebrate Bulgaria's national day each year...
- Bulgarian Air ForceBulgarian Air ForceThe Bulgarian Air Force is a branch of the Military of Bulgaria, the other two being the Bulgarian Navy and Bulgarian land forces. Its mission is to guard and protect the sovereignty of Bulgarian airspace, to provide aerial support and to assist the Land Forces in case of war. The Bulgarian Air...
- Armée de l'Air
- Aéronautique navaleAviation NavaleFrench Naval Aviation of the French Navy includes 206 aircraft and 6,800 men, both civilians and military personnel. They operate from six airbases, five of them in Metropolitan France and one overseas....
- Forces Aériennes Françaises Libres (as trainers only)
Nazi Germany
- LuftwaffeLuftwaffeLuftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....
Kingdom of Italy (Napoleonic)
- Regia AeronauticaRegia AeronauticaThe Italian Royal Air Force was the name of the air force of the Kingdom of Italy. It was established as a service independent of the Royal Italian Army from 1923 until 1946...
Intended operators
Romanian Air Force
Romanian Air Force
The Romanian Air Force is the air force branch of the Romanian Armed Forces. It has an air force headquarters, an operational command, four air bases and an air defense brigade...
Survivors
Dewoitine D.520 n°408- Was restored to flying condition in the 1970s. Delivered in 1940, it fought against Allies in 1942, survived the war and many years later was rebuilt as the N.90, a famous D.520 flown with GC II/3. It was overhauled in 1977-80, and it flew at Le Bourget airshow in 1980. It performed at various airshows in Europe, but was destroyed in a fatal crash in 1986.
Dewoitine D.520 n°603
- On display at the Conservatoire de l'air et de l'espace d'Aquitaine in Bordeaux-Mérignac.
Dewoitine D.520 n°655
- Under restoration at the Naval Museum in RochefortRochefort, Charente-MaritimeRochefort is a commune in southwestern France, a port on the Charente estuary. It is a sub-prefecture of the Charente-Maritime department.-History:...
.
Dewoitine D.520 n°862
- Currently on display at the Musée de l'Air et de l'EspaceMusée de l'Air et de l'EspaceThe French Air and Space Museum is a French museum, located in the south-eastern edge of Le Bourget Airport, north of Paris, and in the commune of Le Bourget. It was created in 1919 from a proposition of Albert Caquot .-Description:Occupying over of land and hangars, it is one of the oldest...
. It has been repainted as n°277 used by GC III/6 in June 1940.
